Archana Gupta

Synthesis of 2-amino-5-chloro-3-(trifluoromethyl)benzenethiol and conversion into 4H-1,4-benzothiazines and their sulfones

The synthesis of 2-amino-5-chloro-3-(trifluoromethyl)benzenethiol was achieved by hydrolytic cleavage of 2-amino-6-chloro-4-(trifluoromethyl)benzothiazole which was prepared by cyclization of 4-chloro-2-(trifluoromethyl)phenylthiourea by bromine in chloroform, the phenylthiourea was prepared by the reaction of 4-chloro-2-(trifluoromethyl)aniline with ammonium thiocyanate in hydrochloric acid. Condensation and oxidative cyclization of 2-amino-5-chloro-3-(trifluoromethyl)benzenethiol with β-diketones/β-ketoesters provided 4H-1,4-benzothiazines. Fluorinated sulfones were obtained by oxidation of the corresponding benzothiazines with 30% hydrogen peroxide in glacial acetic acid. The structures of the newly synthesized compounds were confirmed by spectral studies.

Synthetic and spectral investigation of fluorinated phenothiazines and 4H-1,4-benzothiazines as potent anticancer agents

Abstract The syntheses of fluorinated phenothiazines and fluorinated 1,4-benzothiazines are reported.Fluorinated phenothiazines have been prepared via a Smiles rearrangement of N-formylateddiphenylsulphides, synthesized in turn by condensation of substituted 2-aminobenzenethiolswith 2-chloro-5-trifluoromethylnitrobenzene followed by formylation with formic acid.Fluorinated 4H-1,4-benzothiazines have been prepared by the condensation and oxidativecyclization of substituted 2-aminobenzenethiols with p-fluorobenzoylacetone in DMSO.The reaction is believed to proceed via an enaminoketone system. IR and NMR spectralinvestigations are included.

SYNTHESIS OF 5,8-DICHLORO-3-METHYL-4H-1,4- BENZOTHIAZINES AND THEIR CONVERSION INTO SULFONES

Abstract The present work consists of the one pot synthesis of 5,8-dichloro-3-methyl-4H-1,4-benzothiazines by the condensation and oxidative cyclization of 2-amino-3,6-dichlorobenzenethiol with β-diketones/β-ketoesters in dimethyl sulfoxide and oxidation behaviour of 4H-1,4-benzothiazines by 30% hydrogen peroxide in glacial acetic acid to 1,4-benzothiazine sulfones. The structure of all the newly synthesized compounds has been confirmed by elemental analysis and spectral studies.

Stent-Graft Repair of a Large Cervical Internal Carotid Artery Pseudoaneurysm Causing Dysphagia

Pseudoaneurysms of the cervical internal carotid artery (ICA) are rare and most frequently result from trauma, infection, or sometimes spontaneously. They have the potential to cause life-threatening hemorrhage; thus, their immediate management is necessary. Endovascular treatment by stent graft placement in the affected artery appears to be a safe and effective treatment option. We present a case of a child who presented with neck swelling and dysphagia caused by a ruptured cervical ICA pseudoaneurysm which was managed by stent graft placement.

Regioselective OnePot Synthesis Of 5-Chloro-3-Methyl-8- Trifluoromethyl-4H-1, 4-Benzothiazines

5-Chloro-3-methyl-8-trifluoromethyl-4H-l, 4-benzothiazines have been synthesized by an efficient synthetic method in a single step involving heterocyclization of 2amino-3-chloro-6-trifluoromethylbenzenethiol with D-ketoesters or D-diketones. 2Amino-3-chloro-6-trifluoromethylbenzenethiol was prepared by hydrolytic cleavage of 2-amino-4-chloro-7-trifluoromethylbenzothiazole which in turn was prepared by brominative cyclization of 2-chloro-5-trifluoromethylphenylthiourea. The phenylthiourea was prepared by the reaction of 2-chloro-5-trifluoromethylaniline with ammonium thiocyantate. The structures of the synthesized 4H-1, 4-benzothiazines have been characterized by their elemental analyses and spectral characteristics.

Synthesis of Crown Ethers Embodied Adamantane and Homoadamantane Skeletons (1)

Adamantano[2,4]-16-crown-5 and -19-crown-6 ethers 5, 6, and homoadamantano[4,5]15-crown-5 and -18-crown-6 ethers 11, 12 have been prepared and their some cation binding properties have been discussed based on the preliminary solvent extraction and PM3 calculation results.

ONE - POT SYNTHESIS OF 3,5-DIMETHYL/ 3,7-DIMETHYL-4H-1,4-BENZOTHIAZINES

Synthesis of 3,5-dimethyl / 3,7-dimethyl-4H-l,4-benzo-thiazines is reported by the condensation and oxidative cyclization of 2-amino-3-methyl / 5methylbenzenethiols with compounds containing active methylene group in dimethylsulfoxide. The reactions proceed through the formation of intermediate enaminoketones. The compounds containing active methylene group viz. benzoylacetones have been prepared by the Claisen condensation of acetophenones with ethylacetate. The IR, NMR and Mass spectral studies are also included. INTRODUCTION 4H-l,4-Benzothiazines constitute an interesting class of heterocycles. They are anticipated to exhibit pharmacological activities (1,2). These are used as central nervous system depressants, antispasmodics, antiulcer, antidermatosis, antiinflammatories, antihistaminics etc. Besides pharmacological activities, they are having industrial applications (3). Some benzothiazines have shown significant effects against cancer (4,5). A slight change in substitution pattern in benzothiazine nucleus causes marked difference in their activities. Therefore, we have synthesized some hitherto unknown title benzothiazines to make them available for biological screening. RESULTS AND DISCUSSION The title benzothiazines have been synthesized by 2-amino-3-methyl / 5methylbenzenethiols which were prepared by the hydrolytic cleavage of 2-amino-4methy / 6-methylbenzothiazoles respectively by adopting the method reported elsewhere (6). 3,5-Dimethyl / 3,7-dimethyl-4H-l,4-benzothiazines (VIIa-h) have been synthesized by the condensation of ß-diketones (III) (viz. 3-bromo-benzoylacetone, 3methylbenzoylacetone, 4-ethoxybenzoylacetone or 4-ethylbenzo-ylacetone) with 2amino-3-methyl / 5-methylbenzenethiol (I) (Scheme 1) in dimethyl-sulfoxide which causes oxidative cyclization. Each reaction involves the formation of an intermediate enaminoketone (V). Under the experimental conditions 2-aminobenzenethiols (I) are readily oxidised to bis(2-aminophenyl)disulfides(II) which cyclizes to 4H-1,4benzothiazines (VII) by scission of sulphur-sulphur bond due to high reactivity of exposition of enaminoketone systems (III) towards nucleophilic attack.

Testicular tumors: A histopathological study of 50 cases

Background: Pattern of a disease is studied with the idea of getting information about the clinical presentation, the morphology and the causative factors. The testicular tumors constitute 4 most common cause of death from neoplasia in younger males. Though the etiology of testicular cancers is not well understood, various factors like cryptorchidism, trauma infections and genetics play role in the disease. The testicular tumors are histologically diverse. Aim: Our study was undertaken to study the clinical presentation and morphological patterns of the testicular tumors. A total number of 50 cases of testicular tumors were studied. The majority of the cases i.e. 48 (96%) were of germ cell origin. Only 2 cases (4%) of testicular lymphoma were reported. Materials and Methods: The study was carried out in two parts – retrospective (2005-2007) and prospective (2008-2010). During this period a total number of 50 cases of testicular tumors were diagnosed on small biopsies and orchidectomy specimens. Results: The study work comprised of 50 cases of testicular tumors among which 44 (88%) cases were malignant and 6 (12%) were benign (Table 1). The majority of the testicular tumors i.e. 48 cases (96%) were of germ cell origin. Only 2 cases (4%) of testicular lymphoma were reported (Table 2). No case of sex cord stromal tumor, mixed germ cell sex cord tumor and metastatic tumor was reported. Conclusion: Tumors of the testes present a great variety of histological types with many structural variations. The present study fairly provides an insight into the clinical presentations, prevalence and patterns of testicular tumors.